In the Linux kernel, the following vulnerability has been resolved:
x86/mm: Don't apply va_align to hugetlb mappings on AMD F15h
get_align_mask() returns huge_page_mask_align() for hugetlbfs, but get_align_bits()
adds va_align.bits regardless, so vm_unmapped_area() returns an address off the huge
page boundary and __unmap_hugepage_range() hits BUG_ON(start & ~huge_page_mask(h)) at
teardown.
This can be triggered on Carrizo and FX-8370E, both hstates.
Pass the file to get_align_bits() and skip the randomisation for hugetlbfs.
[ bp: Massage commit message. ]